Tom Tromey wrote:
* Why put the optimization diary into the object file? Why not just have -Wdiary and print it along with all the warnings? (I'm sure there's an answer to this, it would just be nice if it were in the document...)
These are not warnings and they should not cause build failures when -Werror is used, hence warnings are not suitable medium to communicate this info.
However, GCC provides hints along with warnings and errors. But they all reside in build log. While doing performance analysis, build log may not be available hence it is required to have it on disk somewhere. And text format is not suitable because of two reasons: 1) It is verbose. Try -opt_report in ICC. 2) This info is consumed by other tools (e.g. IDE, performance analyzer). It makes sense for a tool like Shark to use dwarf reader to get this info then parse raw text output. So, if 1) we need to keep this info on disk and available with final binary and 2) we use binary format to encode this info) then dwarf in object file is a natural selection. Command line developer can use extended dwarf reader to get the text messages. - Devang
